An air-fuel ratio is a critical parameter for operating an engine, and may vary based on power requirements. It is relevant to ensure a suitable air-fuel ratio for an effective operation of the engine at all times. Any undesirable change in the air-fuel ratio may hamper operations of the engine and may even lead to damage to the engine. In order to monitor the air-fuel ratio, quality measurement sensors are disposed in the engine. In some cases, a quality measurement sensor is installed in an exhaust system of the engine. In such cases, undesired emission, due to the combustion of an air-fuel mixture, may have already occurred by the time the quality measurement sensor detects inappropriate air-fuel ratio. Alternatively, the quality measurement sensor may be installed in a fuel supply system of the engine, with one or two shut-off valves and a conduit for measuring quality of the fuel. Installation, operation, and maintenance of such shut-off valves and the conduit is a cumbersome and expensive task. This would lead to economical loss, unnecessary downtime, inconvenience, and ineffective operations of the engine.
U.S. Pat. No. 7,210,455 (the '455 patent) discloses a system that uses a fuel quality sensor to control various aspects of engine operation. In this regard, an acoustic wave sensor is used to measure viscosity and density of gasoline fuels. The measured viscosity and density, of gasoline fuels, are to predict engine combustion quality during an engine start. Based on the prediction, engine operating parameters (such as fuel injection amount and ignition timing) are adjusted for achieving improved vehicle driveability and engine combustion. However, the system of the '455 patent offers a fragmented and a relatively inaccurate approach for measuring the quality of the fuel in a fuel tank of the engine.